1 files changed, 169 insertions, 0 deletions

diff --git a/src/eddsa.c b/src/eddsa.c
new file mode 100644
index 0000000..92a0222
--- /dev/null
+++ b/src/eddsa.c
@@ -0,0 +1,169 @@
+/*
+ * Copyright (c) 2019 Yubico AB. All rights reserved.
+ * Use of this source code is governed by a BSD-style
+ * license that can be found in the LICENSE file.
+ */
+
+#include <openssl/bn.h>
+#include <openssl/ec.h>
+#include <openssl/evp.h>
+#include <openssl/obj_mac.h>
+
+#include <string.h>
+#include "fido.h"
+#include "fido/eddsa.h"
+
+#if defined(LIBRESSL_VERSION_NUMBER) || OPENSSL_VERSION_NUMBER < 0x10101000L
+EVP_PKEY *
+EVP_PKEY_new_raw_public_key(int type, ENGINE *e, const unsigned char *key,
+    size_t keylen)
+{
+        (void)type;
+        (void)e;
+        (void)key;
+        (void)keylen;
+
+        return (NULL);
+}
+
+int
+EVP_PKEY_get_raw_public_key(const EVP_PKEY *pkey, unsigned char *pub,
+    size_t *len)
+{
+        (void)pkey;
+        (void)pub;
+        (void)len;
+
+        return (0);
+}
+
+int
+EVP_DigestVerify(EVP_MD_CTX *ctx, const unsigned char *sigret, size_t siglen,
+    const unsigned char *tbs, size_t tbslen)
+{
+        (void)ctx;
+        (void)sigret;
+        (void)siglen;
+        (void)tbs;
+        (void)tbslen;
+
+        return (0);
+}
+#endif /* LIBRESSL_VERSION_NUMBER || OPENSSL_VERSION_NUMBER < 0x10101000L */
+
+#if OPENSSL_VERSION_NUMBER < 0x10100000L
+EVP_MD_CTX *
+EVP_MD_CTX_new(void)
+{
+        return (NULL);
+}
+
+void
+EVP_MD_CTX_free(EVP_MD_CTX *ctx)
+{
+        (void)ctx;
+}
+#endif /* OPENSSL_VERSION_NUMBER < 0x10100000L */
+
+static int
+decode_coord(const cbor_item_t *item, void *xy, size_t xy_len)
+{
+        if (cbor_isa_bytestring(item) == false ||
+            cbor_bytestring_is_definite(item) == false ||
+            cbor_bytestring_length(item) != xy_len) {
+                fido_log_debug("%s: cbor type", __func__);
+                return (-1);
+        }
+
+        memcpy(xy, cbor_bytestring_handle(item), xy_len);
+
+        return (0);
+}
+
+static int
+decode_pubkey_point(const cbor_item_t *key, const cbor_item_t *val, void *arg)
+{
+        eddsa_pk_t *k = arg;
+
+        if (cbor_isa_negint(key) == false ||
+            cbor_int_get_width(key) != CBOR_INT_8)
+                return (0); /* ignore */
+
+        switch (cbor_get_uint8(key)) {
+        case 1: /* x coordinate */
+                return (decode_coord(val, &k->x, sizeof(k->x)));
+        }
+
+        return (0); /* ignore */
+}
+
+int
+eddsa_pk_decode(const cbor_item_t *item, eddsa_pk_t *k)
+{
+        if (cbor_isa_map(item) == false ||
+            cbor_map_is_definite(item) == false ||
+            cbor_map_iter(item, k, decode_pubkey_point) < 0) {
+                fido_log_debug("%s: cbor type", __func__);
+                return (-1);
+        }
+
+        return (0);
+}
+
+eddsa_pk_t *
+eddsa_pk_new(void)
+{
+        return (calloc(1, sizeof(eddsa_pk_t)));
+}
+
+void
+eddsa_pk_free(eddsa_pk_t **pkp)
+{
+        eddsa_pk_t *pk;
+
+        if (pkp == NULL || (pk = *pkp) == NULL)
+                return;
+
+        explicit_bzero(pk, sizeof(*pk));
+        free(pk);
+
+        *pkp = NULL;
+}
+
+int
+eddsa_pk_from_ptr(eddsa_pk_t *pk, const void *ptr, size_t len)
+{
+        if (len < sizeof(*pk))
+                return (FIDO_ERR_INVALID_ARGUMENT);
+
+        memcpy(pk, ptr, sizeof(*pk));
+
+        return (FIDO_OK);
+}
+
+EVP_PKEY *
+eddsa_pk_to_EVP_PKEY(const eddsa_pk_t *k)
+{
+        EVP_PKEY *pkey = NULL;
+
+        if ((pkey = EVP_PKEY_new_raw_public_key(EVP_PKEY_ED25519, NULL, k->x,
+            sizeof(k->x))) == NULL)
+                fido_log_debug("%s: EVP_PKEY_new_raw_public_key", __func__);
+
+        return (pkey);
+}
+
+int
+eddsa_pk_from_EVP_PKEY(eddsa_pk_t *pk, const EVP_PKEY *pkey)
+{
+        size_t len = 0;
+
+        if (EVP_PKEY_get_raw_public_key(pkey, NULL, &len) != 1 ||
+            len != sizeof(pk->x))
+                return (FIDO_ERR_INTERNAL);
+        if (EVP_PKEY_get_raw_public_key(pkey, pk->x, &len) != 1 ||
+            len != sizeof(pk->x))
+                return (FIDO_ERR_INTERNAL);
+
+        return (FIDO_OK);
+}